Screen: init

1 files changed, 32 insertions, 0 deletions

diff --git a/Screen.hs b/Screen.hs
new file mode 100644
index 0000000..2bf0329
--- /dev/null
+++ b/Screen.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE RecordWildCards #-}
+module Screen (Screen(..), setScreen, withScreen) where
+
+import Control.Exception
+import Data.List
+import System.IO
+
+data Screen = Screen
+    { stdinEcho :: Bool
+    , stdinBufferMode :: BufferMode
+    , stdoutBufferMode :: BufferMode
+    , decsetPm :: [Int]
+    , decrstPm :: [Int]
+    }
+
+setScreen :: Screen -> IO Screen
+setScreen Screen{..} = get <* set where
+  get = Screen <$> hGetEcho stdin
+               <*> hGetBuffering stdin
+               <*> hGetBuffering stdout
+               <*> pure decrstPm
+               <*> pure decsetPm
+  set = do
+      hSetEcho stdin stdinEcho
+      hSetBuffering stdin stdinBufferMode
+      hSetBuffering stdout stdoutBufferMode
+      hPutStr stdout $ "\ESC[?" ++ intercalate ";" (map show decsetPm) ++ "h"
+      hPutStr stdout $ "\ESC[?" ++ intercalate ";" (map show decrstPm) ++ "l"
+      hFlush stdout
+
+withScreen :: Screen -> (Screen -> IO a) -> IO a
+withScreen s = bracket (setScreen s) setScreen